The present invention relates to temperature measurement, and in particular, to temperature measurement of a turbine section of a gas turbine engine. A gas turbine engine typically has a compressor section, which compresses and supplies gas to a burner or combustor section, which adds fuel, combusts the gas and supplies the gas to a turbine section, which extracts energy from the hot compressed gas to drive the compressor section and other components depending on the application. Temperature sensors are placed at various portions of the gas turbine engine to provide temperature feedback for various components as well as the gas as it flows along its flow-path.
In some gas turbine engines an array of thermocouples is positioned circumferentially around the turbine section. The thermocouples are typically wired together in parallel, using expensive thermocouple wire and further requiring a cold junction RTD (resistance temperature detector) reference circuit. The array averages the temperature sensed by each thermocouple to create an average temperature. However, if one of the thermocouples fails, the average sensed temperature can drift to a value higher or lower than what would be determined if all thermocouples were functional. Moreover, it may not be readily apparent that one or more thermocouples have failed until the last thermocouple in the array fails. Thus, such thermocouple circuits can be relatively expensive, inaccurate, and unreliable.